CT pulmonary angiography and perfusion scanning have equivalent clinical negative predictive value (99% for CT pulmonary angiography; 100% for perfusion scanning) and image quality in the care of pregnant patients. Therefore, the choice of study should be based on other considerations, such as radiation concern, radiographic results, alternative diagnosis, and equipment availability. Reducing the amount of radiation to the maternal breast favors use of perfusion scanning when the radiographic findings are normal and there is no clinical suspicion of an alternative diagnosis.

Controversy exists concerning the advantages and appropriateness of current imaging modalities of the localization of parathyroid tumors. We conducted a prospective, blinded study to compare the efficacy of 3 different imaging modalities in 40 patients with primary hyperparathyroidism (HPT). Patients with HPT were examined preoperatively by computer‐assisted thallium‐201/technetium‐99m scintigraphy (TTS), high‐resolution (GE 9800) computed tomography (CT), and high‐resolution (7.5 MHz) real‐time sonography (US). Each study was performed and interpreted independently. These patients then had a neck exploration and parathyroidectomy which allowed for clinical correlation of pathologic findings with the imaging results. Overall sensitivities of the 3 imaging modalities were TTS‐72%, CT‐72%, and US‐57%, with specificities of TTS‐93%, CT‐92%, and US‐96%. For lesions located below the thyroid (thymic tongue and mediastinum), sensitivities were TTS‐86%, CT‐29%, and US‐20%, all with specificities of 100%. In those HPT patients presenting with prior failed neck explorations, parathyroid tumors were detected with sensitivities of TTS‐88%, CT‐57%, and US‐67%, with specificities of 100%, 71%, and 100%, respectively. TTS with subsequent CT appears to be an optimal imaging strategy for HPT patients with prior failed neck explorations or suspected lesions below the thyroid. Since surgeons experienced in parathyroid surgery have a cure rate of 93% or greater in HPT patients without prior neck exploration, these imaging modalities may not be cost‐effective and thus not indicated for these patients.

Unexpectedly, more patients with autonomic dysfunction have rapid rather than delayed gastric emptying. The presence of diarrhea in patients with autonomic symptoms should prompt consideration for the presence of rapid gastric emptying. Conversely, the finding of rapid gastric emptying in patients with gastrointestinal symptoms should prompt consideration for the presence of underlying autonomic dysfunction.

Multidetector computerized tomography urography is relatively sensitive and highly specific for detecting urinary neoplasms. It may serve as the primary imaging modality to evaluate patients with hematuria. Multidetector computerized tomography urography does not eliminate the role of cystoscopy in the evaluation of hematuria.